The disclosed embodiments of the present invention relate to wireless communications, and more particularly, to a wireless communication receiver having one signal processing circuit whose operation mode is adjusted by monitoring a signal level of a specific signal of a preceding signal processing circuit and related wireless communication method.
A wireless communication receiver is devised for receiving a wanted signal in a wanted frequency band. However, the existence of a large blocker signal may significantly degrade the performance of the wireless communication receiver. For example, when there is a large blocker signal beside the small wanted signal, the gain compression resulted from the nonlinearity of the active components within the wireless communication receiver may make the wanted signal smaller. In addition, the blocker signal may induce additional noise due to the nonlinearity of the active components. To solve above problems, the conventional solution is to improve the linearity of the wireless communication receiver. Moreover, reciprocal mixing in the wireless communication receiver may also induce additional noise. To solve this problem, the conventional solution is to improve the phase noise of the local oscillator (LO) signal.
In most of the cases, improving the linearity of the wireless communication receiver and the phase noise of the LO signal is at the expense of more current. This leads to larger power consumption, inevitably. Consider a case where a wireless communication receiver receives large blocking signal beside the wanted signal. To deal with the large blocking signal, in general, the mixer module in the receiver has to use large-sized switches (transistors) to improve the linearity. Unfortunately, large-sized switches (transistors) have parasitical capacitors with larger capacitive values, resulting in a heavy load to the LO signal generator. Thus, the LO signal generator is required to consume more current for successfully driving the large-sized switches (transistors). If the phase noise improvement of the LO signal is also taken into consideration, the total power consumption of the LO signal generator would be quite large.
However, under most operating conditions, the linearity and phase noise performance exceeds what is actually needed since the existence of strong blocking signals is rare. Therefore, there is a need for an innovative receiver design which can adaptively adjust the power consumption of a wireless communication receiver according to an actual operating condition of the wireless communication receiver.